3-Inch Toilet Flush Valve Replacement 2-piece Toilet Tank Parts with Gasket and Bolts Fit for American Standard 738921-100.0070A Easy to Install High Performance Water-Saving - - Amazon.com
TOTO THU451.10A-A N/A Replacement One Piece Toilet Flush Valve - FaucetDirect.com
KOHLER K-1083980 3" Toilet Canister Flush Valve Kit | General Plumbing Supply, Inc.
Toilet Parts: What They Are and Common Fixes | Family Handyman